forked from Bananymous/banan-os
114 lines
2.4 KiB
C++
114 lines
2.4 KiB
C++
#include <kernel/PIC.h>
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#include <kernel/IDT.h>
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#include <kernel/IO.h>
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#define PIC1 0x20 /* IO base address for master PIC */
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#define PIC2 0xA0 /* IO base address for slave PIC */
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#define PIC1_COMMAND PIC1
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#define PIC1_DATA (PIC1+1)
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#define PIC2_COMMAND PIC2
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#define PIC2_DATA (PIC2+1)
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#define PIC_EOI 0x20 /* End-of-interrupt command code */
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#define ICW1_ICW4 0x01 /* ICW4 (not) needed */
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#define ICW1_SINGLE 0x02 /* Single (cascade) mode */
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#define ICW1_INTERVAL4 0x04 /* Call address interval 4 (8) */
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#define ICW1_LEVEL 0x08 /* Level triggered (edge) mode */
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#define ICW1_INIT 0x10 /* Initialization - required! */
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#define ICW4_8086 0x01 /* 8086/88 (MCS-80/85) mode */
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#define ICW4_AUTO 0x02 /* Auto (normal) EOI */
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#define ICW4_BUF_SLAVE 0x08 /* Buffered mode/slave */
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#define ICW4_BUF_MASTER 0x0C /* Buffered mode/master */
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#define ICW4_SFNM 0x10 /* Special fully nested (not) */
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namespace PIC
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{
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void Remap()
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{
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uint8_t a1 = IO::inb(PIC1_DATA);
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uint8_t a2 = IO::inb(PIC2_DATA);
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// Start the initialization sequence (in cascade mode)
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IO::outb(PIC1_COMMAND, ICW1_INIT | ICW1_ICW4);
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IO::io_wait();
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IO::outb(PIC2_COMMAND, ICW1_INIT | ICW1_ICW4);
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IO::io_wait();
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// ICW2
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IO::outb(PIC1_DATA, IRQ_VECTOR_BASE);
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IO::io_wait();
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IO::outb(PIC2_DATA, IRQ_VECTOR_BASE + 0x08);
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IO::io_wait();
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// ICW3
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IO::outb(PIC1_DATA, 4);
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IO::io_wait();
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IO::outb(PIC2_DATA, 2);
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IO::io_wait();
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// ICW4
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IO::outb(PIC1_DATA, ICW4_8086);
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IO::io_wait();
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IO::outb(PIC2_DATA, ICW4_8086);
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IO::io_wait();
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// Restore original masks
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IO::outb(PIC1_DATA, a1);
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IO::outb(PIC2_DATA, a2);
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}
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void MaskAll()
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{
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IO::outb(PIC1_DATA, 0xff);
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IO::outb(PIC2_DATA, 0xff);
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}
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void EOI(uint8_t irq)
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{
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if (irq >= 8)
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IO::outb(PIC2_COMMAND, PIC_EOI);
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IO::outb(PIC1_COMMAND, PIC_EOI);
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}
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void Mask(uint8_t irq) {
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uint16_t port;
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uint8_t value;
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if(irq < 8) {
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port = PIC1_DATA;
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} else {
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port = PIC2_DATA;
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irq -= 8;
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}
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value = IO::inb(port) | (1 << irq);
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IO::outb(port, value);
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}
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void Unmask(uint8_t irq) {
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uint16_t port;
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uint8_t value;
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if(irq < 8) {
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port = PIC1_DATA;
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} else {
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port = PIC2_DATA;
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irq -= 8;
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}
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value = IO::inb(port) & ~(1 << irq);
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IO::outb(port, value);
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}
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uint16_t GetISR()
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{
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IO::outb(PIC1_COMMAND, 0x0b);
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IO::outb(PIC2_COMMAND, 0x0b);
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uint8_t isr0 = IO::inb(PIC1_COMMAND);
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uint8_t isr1 = IO::inb(PIC2_COMMAND);
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return (isr1 << 8) | isr0;
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}
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} |